During the first year of the contract, the synthesis of the following four compojnds in two gram amounts is required: 1,2,3,4,6,7,9-Heptachlorodibenzo(p)dioxin; 1,2,3,6,7,8-Hexachlorodibenzo(p)dioxin; 1,2,3,7,8,9-Hexachlorodibenzo( ) dioxin; 1,2,3,6,8,9-Hexachlorodibenxo(p)dioxin. The second year of the contract will be devoted to the synthesis of 1,2,4,6,7,9-Hexachlorodibenzo(p)dioxin and the synthesis of other compojnds which will include chlorinated dibenzofurans and possibly C1-37 labeled dioxins in 2 grams amounts. All facilities devoted to this project must comply with OSHA regulaties for handling carcinogenic materials. The compounds should be minimum 96% pure. In addition, a determination should be made of the identity and amount of various impurities present in the compounds synthesized. Analytical support facilities are required for performing complete chemical characterization studies on each compounds.